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authorTerry Barnaby <terry@beam.ltd.uk>2013-04-08 12:05:47 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-05-07 19:51:57 -0700
commit37f8417572877c7c8c58400d2779248f1f7d74ed (patch)
treea39817c443caee70446f77ae113c366bdc0fb762
parent217fd3afce27de54b0b10fc33ce6268c999dbdb4 (diff)
mmc: atmel-mci: pio hang on block errors
commit bdbc5d0c60f3e9de3eeccf1c1a18bdc11dca62cc upstream. The driver is doing, by default, multi-block reads. When a block error occurs, card/block.c instigates a single block read: "mmcblk0: retrying using single block read". It leaves the sg chain intact and just changes the length attribute for the first sg entry and the overall sg_len parameter. When atmci_read_data_pio is called to read the single block of data it ignores the sg_len and expects to read more than 512 bytes as it sees there are multiple items in the sg list. No more data comes as the controller has only been commanded to get one block. Signed-off-by: Terry Barnaby <terry@beam.ltd.uk> Acked-by: Ludovic Desroches <ludovic.desroches@atmel.com> Signed-off-by: Chris Ball <cjb@laptop.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/mmc/host/atmel-mci.c14
1 files changed, 10 insertions, 4 deletions
diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c
index cc867e664b01..2a822d9e4684 100644
--- a/drivers/mmc/host/atmel-mci.c
+++ b/drivers/mmc/host/atmel-mci.c
@@ -165,6 +165,7 @@ struct atmel_mci {
void __iomem *regs;
struct scatterlist *sg;
+ unsigned int sg_len;
unsigned int pio_offset;
struct atmel_mci_slot *cur_slot;
@@ -754,6 +755,7 @@ static u32 atmci_prepare_data(struct atmel_mci *host, struct mmc_data *data)
data->error = -EINPROGRESS;
host->sg = data->sg;
+ host->sg_len = data->sg_len;
host->data = data;
host->data_chan = NULL;
@@ -1592,7 +1594,8 @@ static void atmci_read_data_pio(struct atmel_mci *host)
if (offset == sg->length) {
flush_dcache_page(sg_page(sg));
host->sg = sg = sg_next(sg);
- if (!sg)
+ host->sg_len--;
+ if (!sg || !host->sg_len)
goto done;
offset = 0;
@@ -1605,7 +1608,8 @@ static void atmci_read_data_pio(struct atmel_mci *host)
flush_dcache_page(sg_page(sg));
host->sg = sg = sg_next(sg);
- if (!sg)
+ host->sg_len--;
+ if (!sg || !host->sg_len)
goto done;
offset = 4 - remaining;
@@ -1659,7 +1663,8 @@ static void atmci_write_data_pio(struct atmel_mci *host)
nbytes += 4;
if (offset == sg->length) {
host->sg = sg = sg_next(sg);
- if (!sg)
+ host->sg_len--;
+ if (!sg || !host->sg_len)
goto done;
offset = 0;
@@ -1673,7 +1678,8 @@ static void atmci_write_data_pio(struct atmel_mci *host)
nbytes += remaining;
host->sg = sg = sg_next(sg);
- if (!sg) {
+ host->sg_len--;
+ if (!sg || !host->sg_len) {
atmci_writel(host, ATMCI_TDR, value);
goto done;
}